Effects of post sentiment measures over time
engagement index, dependent variable 1. e_index_mean: per post e_index average per month (“raw engagement scores”) 2. e_index_mean_norm: normalized per organization values of e_index_mean (1. above) 3. e_index_norm_mean: per post e_index normalized per organization average per month 4. e_index_rel_mean: per post e_index relative to follower count average per month